Weathering Steel

Also referred to as Atmospheric Corrosion Resistant Steel, this product is seen as an inexpensive and highly effective material to be used in structural applications which are exposed to the atmospheric elements.

The steel oxidises with pollutants in the air forming a thick layer of rust – this formation acts as a protective layer which prevents the steel from corroding. The layer constantly regenerates and forms over time.

Weathering steel is therefore classed as being a ‘self–protecting’ steel. In normal use the material does not need painting or other external treatment any kind.

Weather resistant steel can be used in a wide range of structural applications. It is a commonly used product in bridge construction because of the lack of maintenance costs. It is also popular in modern architecture where the aesthetically pleasing finish is in great demand for sculptural buildings and fascias.

Masteel offers an extensive range of abrasion resistant steel with the following benefits…

  • major stockholding
  • global shipping
  • variety of plate widths
  • extensive range of thicknesses
  • quick turnaround
  • accurate ‘in-house’ cutting and profiling service
  • high quality steel from major European steel mills

Corten Steel

Corten Steel

Corten steel (often referred to as Cor–Ten) is a weather resistant steel which could more accurately be termed as an “Atmospheric Corrosion Resistant Steel”.

It is a copper chromium alloy steel – this alloy displays a greater level of resistance to atmospheric weathering when compared to other unalloyed steels. It’s chemical composition promotes the early formation of an adhering protective layer of rust when exposed to the elements.

Aesthetically pleasing to the eye, this finish has become popular with many high profile architects and has been specified and used in a variety of applications in including building fascias, architectural sculptures and bridges.

Examples of Corten Structures

 

 

The protective layer of Corten constantly develops and regenerates over time, reacting to the pollutants in the atmosphere. Consideration should be made with regard to the thicknesses used especially when the material is utilised for structural rather than solely cosmetic purposes.

The benefits of such a steel are immediately obvious – a self–protecting steel is economic, long lasting and easily recyclable.

Our Corten Steel Grades

 

Corten A

Corten A Weathering Steel

Corten A – a weather resistant steel created by alloying copper, chromium and nickel. In addition to this, Corten A has added phosphorous which makes the material best suited for gas flue applications and for aesthetic facias The material is not recommended in heavy load bearing applications – in this case Corten B or S355J2W should be considered.

The top layer of the material reacts with atmospheric elements to form a rust coloured protective layer which not only makes the steel virtually maintenance free but also provides a pleasing and consistent finish.

 

Grades & Equivalents

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Mechanical Properties

GradeThickness (mm)
Strip Products
Plate ProductsYield Strength
Rel N/mm²
Minimum
Tensile Strength
Rm N/mm²
Minimum
Elongation
A50 %
Minimum
Corten A2-126-1234548520

Chemical Composition of Corten A

  
C0.15
Si0.25/0.75
Mn0.20/0.50
P0.07/0.15
S0.030
Al0.015/0.06
Cu0.25/0.55
Cr0.50/1.25
Ni0.65

Corten B

Corten B

Corten B – a weather resistant steel which is better suited for heavy and load bearing structures.

The material forms its own protective layer when exposed to atmospheric elements. Essentially, the top layer corrodes which then protects the steel beneath it. The natural finish does not normally require any form of maintenance such as painting, which makes the material a highly cost effective alternative to other structural steels.

Painting and maintenance will be required if the structure is is continually wet as a protective layer will not form. An good example is where the base of the structure meets with the ground or is partially submerged.

Please refer to the technical specifications below.

Grades & Equivalents

CortenEN 10025-5:2004
Corten BS355J2W

Mechanical Properties

GradeThickness (mm)
Strip Products
Plate ProductsYield Strength
Rel N/mm²
Minimum
Tensile Strength
Rm N/mm²
Minimum
Elongation
A50 %
Minimum
Corten B2-136-4034548519

Chemical Composition of Corten B

 %
C0.19
Si0.30/0.65
Mn0.80/1.25
P0.035
S0.030
Al0.020/0.06
V0.02/0.10
Cu0.25/0.40
Cr0.40/0.65
Ni0.40

S355JOWP

S355JOWP

S355J0WP is a structural weathering steel which is also referred to as atmospheric corrosion resistant steel. The main alloying elements are chromium nickel and copper with added phosphorous which gives it excellent self protecting qualities. As the steel reacts with elements in the atmosphere, the material forms a layer of rust over time which in essence protects the steel from corrosion.

S355J0WP (which is an equivalent grade to Corten A) provides a long lasting and economic structural steel solution for use in applications such as steel bridges stack gas applications and in steel sculptured buildings due to the material’s aesthetically pleasing finish.

Grades & Equivalents

EN 10025-5:2004Corten
S355JOWPCorten A

Mechanical Properties of S355JOWP

GradeMin. Yield Strength ReH MPa     Tensile Strength Rm MPa  
Nominal Thickness (mm)Nominal Thickness (mm)
<16>16 <40>40 <63>63 <80>80 <100>100 <150>3>3 <100>100 <150
S355JOWP355345510/680470/630

Chemical Composition of S355JOWP

 %
C0.12
Si0.75
Mn1.00
P0.06/0.15
S0.035
N0.009
Cr0.30/1.25
Cu0.25/0.55

S355JOW

S355JOW Weathering Steel

Like S355J0WP, S355J0W is a weathering steel and is an equivalent to Corten B.

As the material rusts when exposed to atmospheric elements, the material builds its own protective layer which prevents the steel from further oxidation. Therefore S355J0W, like all weathering steels, offers excellent, cost effective protection against atmospheric conditions without the need for painting or external treatment.

S355J0WP tends to be used for structures which use thinner materials.

Grades & Equivalents

EN 10025-5:2004Corten
S355JOWCorten B

Mechanical Properties of S355JOW

GradeMin. Yield Strength ReH MPa     Tensile Strength Rm MPa  
Nominal Thickness (mm)Nominal Thickness (mm)
<16>16 <40>40 <63>63 <80>80 <100>100 <150>3>3 <100>100 <150
S355JOWP355345335325315295510/680470/630450/600

Chemical Composition of S355JOW

 %
C0.16
Si0.50
Mn0.50/1.50
P0.035
S0.035
N0.009
Cr0.40/0.80
Cu0.25/0.55

S355J2W

S355J2W

S355J2W is weather resistant steel which is intended for use in load bearing or heavy structures due to its greater tested impact strength. It is also suitable for low temperature working environments.

Like all weather resistant steels, S355J2W is self protecting – the material rusts over time due to the reaction with chemical elements in the air. This rust layer acts a protective barrier which prevents further oxidation. The steel is economical to use and is fully recyclable. As a structural steel it is can be used as easily for load bearing duties as it can for purely cosmetic purposes.

Benefits of Using S355J2W
  • Excellent impact strength
  • Ideal for heavy use or in low temperature
  • Can be used in–situ without the need for expensive treatment or painting over time
  • Popular material with architects for use in steel sculptures and modern structures due to aesthetic appeal

Grades & Equivalents

EN 10025-5:2004Corten
S355J2WCorten B

Mechanical Properties of S355J2W

GradeMin. Yield Strength ReH MPa     Tensile Strength Rm MPa  
Nominal Thickness (mm)Nominal Thickness (mm)
<16>16 <40>40 <63>63 <80>80 <100>100 <150>3>3 <100>100 <150
S355JOWP355345335325315295510/680470/630450/600

Chemical Composition of S355J2W

 %
C0.16
Si0.50
Mn0.50/1.50
P0.030
S0.030
N0.009
Cr0.40/0.80
Cu0.25/0.55

Whatever your steel requirement or specification, Masteel has the knowledge and resources to provide you with a first class steel supply option.